Aqueous glass-fiber sizing composition containing polymer and cationic deionization product of a vinyl siliconate



llnited States Patent The present invention relates broadly to the artof coating compositions and more particularly to a new and improvedsizing or coating for heat softenable materials which may be appliedduring the formation thereof and which imparts superior lubricativeproperties thereto and substantially improves the adhesion of syntheticresins to said materials.

This application is a continuation of our copending application SerialNo. 344,454, filed March 24, 1953, now abandoned.

Recently there has been shown considerable interest in the use ofcertain organo-silicon compounds as surface active agents in thetreatment of fibrous glass materials prior to their incorporation in aresinous laminate. It has been found that the bonding stren th betweenthe glass and resin may be substantially increased by the application ofthese compounds to glass cloth and that laminates produced therefrom areessentially unaffected by exposure to moisture. One explanation for thepresence of this particularly strong bond is that the silicon portion ofthe organo-silicon compound reacts with and becomes a part of the glasssurface and the double bond in the organic radical of the coatingcompounds tends to react with the plastic or resin to form a strongchemical union between these two materials.

Generally speaking, laminates using fibrous glass cloth have beenprepared by weaving fibrous glass yarns into a fabric. The glass clothis preferably first cleaned by heating or washing to remove such organicmaterials as may be present prior to weaving, thus leaving the surfaceof the fibrous material in a condition to readily react with theorgano-silicon coating material which is then applied to theheat-cleaned or washed glass by any suitable method such as spraying ordipping. The coating thus applied to the fabricated fibers is termed afinish, as distinguished from a size which is applied to the fibrousmaterial during formation thereof.

The treated glass cloth is, by one or more processes, washed to removeundesirable substances, then impregnated with a plastic or resin andbuilt up in layers to the desired thickness and subjected to heat andpressure to produce the final laminated composition.

Now, While glass cloth-resin laminates produced as described above havegained wide acceptance in the art, it is apparent that the directapplication of the organosilicones to the glass fibers as they are drawnfrom the bushing has substantial advantages, primarily in theelimination of the relatively costly steps of heat-cleaning prior to orwashing after the coating operation. Not only are these steps expensive,but they have a tendency to weaken the cloth, thereby reducing theflexural strength values which may be attained for laminates made ofsaid cloth. Further advantages result from surface treatment of thefiber in its freshly formed state since while in this state the fiberhas its highest strength and its most reactive surface. By immediatelyprotecting the fiber surface with a size, most of the original fiberstrength is maintained, and in addition, a better bond between saidsurface and the EQQ organo-silicones results by reason of thereactiveness of the fibrous surface.

However, since any sizing material which is to be applied to glassfibers during the formation thereof must possess certain characteristicsand produce certain desirable results, and these characteristics andresults are not entirely provided by the organo-silicon compounds bythemselves, it logically follows that a number of problems eXist in thedirect application of these compounds to newly formed fibers which arenot present in the after-treatment of glass cloth. First, since a bundleof glass filaments are conventionally drawn from a hot bushing at speedsin the neighborhood to 5000 to 10,000 feet per minute and are groupedinto a single strand at this same speed, it is necessary that a liquidsizing be applied to the filaments which will bind them together into acomposite body and maintain them in this condition during subsequenttwisting, plying, winding, weaving, or further processing operations.The binder or film forming agent must thus impart strand integrity tothe fibers. However, it is also essential that the binder be compatiblewith the resin employed in the formation of glass fiber-resin laminates,should adhere well to the resin even in the presence of moisture, andmust have no deleterious effect upon the organo-silicon compound withwhich it is combined.

Second, the size must also possess as one of its ingredients alubricating material which functions to coat the individual filamentsand protect them against mutual abrasion during the winding, twisting,plying and weaving procedures common to the art. This is particularlyimportant since, should some of the individual filaments be fractured asthe strand passes through the guide eyes of the processing equipment, anoticeable fuzzing of the strand occurs which renders the strandunacceptable to the consumer and suitable for little other than scrapusage. And yet at the same time that the lubricant permits relativemovement of the fibers in the strand and thereby prevents breakage dueto abrasion, it also should not have an adverse effect on the stabilityof the organesilicon or impair the function of the silicon in forming astrong chemical bond with the laminating resin. In addition, thelubricant should not inhibit the adhesive properties of the binder orfilm forming agent in the sizing composition.

Third, it is also desirable that the sizing composition contain, eitherseparately or as a part of the lubricant content, an emulsion polymer orstabilizer for the purpose of wetting the surface of the glass andthereby rendering it amenable to the action of the binder. However, suchstabilizers should dry to a clear transparent film and should not onlybe soluble in the uncured laminating resin,

but should be compatible with the cured resin. In addition, theemulsifier content must be held to a minimum in order to prevent aweakening of the action of the organo-silicon on the glass surface.

It is therefore an important aim of the present invention to provide acoating which. may be readily applied to the glass fibers during theattenuation thereof, and which adequately binds the individual filamentsinto a single strand, lubricates said filaments and thereby preventsmutual abrasion, and modifies the surface characteristics of the glassfibers to improve the adhesion thereto of resinous materials.

It is another object of this invention to provide a sizing compositionfor application to glass fibers at the bushing which need not be removedfrom said fibers prior to their weaving into glass cloth, and whichimparts to the glass fiber strands the desired integrity, lubricity,pliability and abrasion resistance.

Another object of the invention lies in the provision of a sizingcomposition which may be uniformly applied to the surfaces of the glassfibers during the high speed drawing thereof, and which is anessentially stable water dispersion characterized by its failure toliberate or produce undesirable gaseous, liquid or solid residues duringor after the application to the semi-molten filaments.

Still another object of the invention is to provde a glass fiber size ofthe above character which is of universal application to the fibersregardless of their ultimate use, and which has increased stabilityWhile in solution form and also while carried on said fibers.

A further object of the invention is to provide a novel coating orsizing composition for glass fibers comprising a film forming agent,lubricant, and organo-silicone, each of which is compatible with theother and all of which are compatible with laminating resins, varnishesand the like.

A still further object of the invention is in the provision of glassfibers coated with a size comprising the product of heat curing a sizingcomposition of the character described, which fibers have superiorrunning properties in production, and when a part of a plastic laminate,produce a wet strength retention substantially greater than thatprovided by many compositions now used for a similar purpose.

More specific objects and advantages will become apparent as thedescription proceeds.

One generally satisfactory method of producing glass fiber threads orstrands consists in flowing a plurality of streams of molten glass froma bushing or feeder and then attenuating said streams into fine fibersby a rotating drum onto which the fibers are wound. The fibers made bythis process are of relatively great length and are commonly referred toin the art as continuous fibers.

In this process, which is described in the Slayter and Thomas Patent No.2,234,986, the fibers are collected in strand form by passing the sameover a pad or guide which is interposed in spaced relation to thebushing and attenuating drum. This guide or pad conventionally performsthe additional function of applying a lubricant and/or binder to theindividual filaments, and a pad of this character may be employed toapply the sizing composition herein disclosed to said filaments. Or ifdesired, the present composition may be flowed onto the fibers bycontact with a rotatable roller partially immersed in a containercarrying said composition.

The novel glass fiber coating of this invention is also of applicationto fibers formed by methods other than the continuous forming processabove described. Thus, what are known to the trade as staple fibers areproduced by engaging the streams of molten material with a gaseous blastfrom a blower and attenuating them into fibers. In accordance with thismethod, an organic lubricant is sprayed onto the fibers at a point belowthe blower. However, it is within the contemplation of this inventionthat the present sizing composition is an advantageous substitute forsuch a lubricant, and that staple fibers carrying this size are ofimportant application in molded synthetic resinous products as well asin other products.

Regardless, however, of the particular process which is employed in theproduction of the glass fibers, there is accomplished superiorpliability and lubricity, improved binding action and more effectivemodification of the surface characteristics of the glass by providing onthe glass filaments during the attenuation thereof a coating comprisinga stable aqueous vinyl silanol solution or dispersion prepared bycontacting a vinyl siliconate with a hydrogen form of a cationexchanger, an aqueous dispersion of a resinous film-forming agent, and awater-dispersible lubricant of a specified class, the pH of the coatingcomposition being preferably not more than 8.

More specifically, the vinyl silanol utilized in the sizing compositionis that of the type prepared according to the method described in thecopending application of Thomas R. Santelli, Serial 279,470, filed March29, 1952, and assigned to the assignee of the present application, nowabandoned. As disclosed therein, a deionized aqueous vinyl silanoldispersion or solution of superior sta- 4 bility and reactivity withglass is produced by the cationic deionization only of a water-solublevinyl siliconate of a metal of the class consisting of alkali metals andalkaline earth metals by contact with the hydrogen form of a cationexchanger. By this process the metal cations are removed from thesiliconate with the production in one step of a stable vinyl silanolfree of salt-forming metal cations. The resulting aqueous dispersion orsolution of silanol has a pH in the range between 3 and 7, in whichcondition it is sutficiently stable to permit its incorporation and usein a sizing composition. The vinyl silanol in a stable aqueous silanoldispersion produced by this method has an average unit structurecorresponding to the formula wherein m is a number from .05 to 3 and nis a number from 1 to 3.95.

A silanol of the type useful in this invention is preferably derived bythe method of the Santelli application from an alkali metal or alkalineearth metal siliconate. The siliconate in turn is derived by hydrolysisand neutralization of a hydrolyzable silane composition comprising amajor proportion of a trifunctional vinyl silane, i.e. a mono-vinylsil-ane in which the remaining valences are attached to hydrolyzablegroups. Other silanes may be present in minor proportions, andpreferably in proportions less than 25% by weight of the hydrolyzablesilane composition. Such other silanes may include other unsaturatedsilanes such as allyl silanes, saturated alkyl, aryl, andcyclo-aliphatic silanes, and any of these and other silanes havingdiffering degrees of functionality such as saturated and unsaturateddifunctional and monofunctional silanes such as diphenyldiethoxy-silane, diphenyl dichlorosilane, divinyl dichlorosilane,diallyl diethoxysilane, diethyl diethoxysilane, trimethylsilane andothers, and hydrolyzable tetrafunctional silanes such as ethylorthosilicate, silicon tetrachloride, and others. It is preferred to usepure mono-vinyl trifunctional silanes such as vinyl tritchloro-,tribromoor trialkoxy silanes.

For the purposes of this invention, however, regardless of theparticular silanes in the mixture, the hydrolyzable mixture should havean r/Si ratio'between 0.8 and 1.50, and more specifically, between 0.95and 1.25, in order to obtain a silanol having sulficient affinity forboth the glass and the laminating plastic, and which also is dispersablein an aqueous system. In actual production, the use of substantiallypure trifunctional silanes, i.e. those having an r/ Si ratio of about1.0, has provided particularly satisfactory results. The r/ Si ratiomeans the ratio of the total number of non-hydrolyzable groups to thetotal number of silicon atoms in the hydrolyzable mixture, i.e., r isthe total number of non-hydrolyzable groups attached to silicon atoms inthe organo-silicon material and Si is the total number of silicon atomstherein.

HY DROLYZABLE COMPOSiTlON The mono-vinyl trifunctional silanes, whichcomprise the major ingredient of the hydrolyzable silane mixture,include vinyl trichlorosil-ane, vinyl tribromosilane, vinyltriethoxysilane, vinyl tripropoxy silane, vinyl tributoxy silane, vinylmono-chloro diethoxy-silane, vinyl triphenoxysilane, vinyltriacetoxysilane, vinyl triaminosilane, and others. The vinylchlorosilanes are preferred because of their relatively low cost andease of hydrolysis in water or aqueous acid solution, while the vinylalkoxy silanes are preferred because of their ease of hydrolysis inalkaline aqueous solution with the direct formation of a usablesiliconate and an easily recoverable volatile alcohol.

Other silanes which may be utilized include aliphatic trifunctionalsilanes such as methyl trichlorosilane, ethyl trichlorosilane, butyltrichlorosilane, hexyl trichlorosilane, methyl triethoxysilane, ethyltriethoxysilane, butyl tributoxysilane, and others; trifunctionalaromatic silanes such as phenyl trichlcro cue, phenyl triethoxysilane,phenyi rnono-chloro diethoxy silane and others; aliphatic and aromaticdifunct-ional silanes such as dimethyl dichlorosil-ane, diethyldichlorosilane, dimethyl diethoxysilane, dimethyl monochloro silane,diphenyl dichlorosilane, diphenyl diethc *silane, monophenyldichlorosilane, monophenyl diethox sil and others; unsaturated silanessuch as ailyi zoxysilane, methallyl triethoxysilane, methyl vinyldichiorcsilane, ethylvinyl diethoxysilane, and others; and other silanescontaining hydroiyzable amino, acetoxy, and aroxy groups. For thepurposes of this invention, a hydrogen atom attached to silicon isconsidered to be a hydrolyzable group because on treatment with acaustic or base to form the siliconate, the hydrogen atom is liberated.This monophenyl dichlorosilane is believed to be equivalent to phenyltrichiorosilane in the formation of siliconates.

SILICONATE SOLUTION The basic sil-iconate solution can be made in anumber of ways, depending to some degree on the silane startingmaterial. Both the cblorosilanes and alkoxy silanes may first behydrolyzed in water or aqueous acid to obtain a caustic soluble silanolor siloxanol (an undehydrated form of siloxane) which is then mixed withor dissolved in an aqueous caustic or base to obtain a concentratedsiliconate solution free of chloride or other anions. Alkoxy silanes, onthe other hand, may be hydrolyzed in aqueous caustic, alkali metal or akaline earth metal hydroxide to obtain directly. an alcoholic aqueoussiliconate solution from which the alcohol may be removed, if desired,by simple distillation. Either method results in a siliconate solutionusable in the invention. The amino-, acetoxyand aroxy-silanes aresimilarly hydrolyzed in water, aqueous acid or aqueous alkali by eitherof these two general methods with but minor variations in technique, allof which are well understood in the art. Solvents may be utilized, ifdesired.

In the preparation of the vinyl siliconate, sufficient of an alkalimetal base or alkaline earth metal base is utilized to produce awater-soluble siliconate. Usually about one I mol of the base per mol ofthe organosilane, i.e. sufficient to produce a mono-metal salt, ispreferred. However, with silane compositions in which the r/Si ratio ishigher than 1.0, or with highly condensed silanols or siloxanols, theformation of a di-metal or higher salt may be necessary to obtain asiliconate that is water soluble. in any of these a slight excess of thebase over theoretical proportions, for example, to molar excess, ispreferred to insure complete solubility. Although it is not known withcertainty, it is believed that the di-metal and higher salts producesilanols, which on treatment with a cation exchange agent, have a higherproportion of monomer or low molecular weight silanol than thesiliconate salts of lower order. If promptly applied to glass or otherreactive surfaces, a silanol of higher monomer content will exhibitgreater afiinity for said surface and produce a tightly adherent coatingthereon. As used herein, the term siliconate includes the watersolublesalts of siliconic-type acids irrespective of the number of organogroups attached to each silicon atom.

The silicoriate content of solutions made by any of the described orother methods may vary considerably. Vinyl triethoxysilane, for example,can be hydrolyzed directly in aqueous caustic, and the alcoholby-product of hydrolysis removed by distillation, if desired, to producea stable aqueous siliconate solution containing from 0.1 to 55% or moresiliconate solids. At the time that the siliconate solution is treatedwith a cation exchange agent it is preferred to dilute the siliconatesolution to less than 10% concentration and preferably to 5% or less forthe reason that dilute solutions are most efliciently handled inconventional ion-exchange equipment. This is no disadvantage in theproduction of the sizing composition of this invention, however, sincethe silanol content of the latter is usually of the same order. Beforemixing with the other size ingredients it may be desirable to furtherdilute the ion-exchanged silanol solution or dispersion.

As described in the noted Santelli application, the siliconate itselfmay be made by mixing, for example, vinyl triethoxysilane (190 grams) ina flask with water (168 grams) containing sodium hydroxide (40 grams)and ethanol cc.) and distilling the resulting mixture until grams of 90%ethanol have been recovered. Sixty grams of the vinyl silicouate thusprepared may then be diluted to comprise about 98% water, and drawn withsuction through a glass tube approximately two and one-half inches indiameter and thirty inches in length that isone-half filled with acationic exchanger, as for example, the hydrogen form of a sulfonic acidcation exchanger such as the sulfonated coals.

The film forming ingredient should, as noted above, be capable of airdrying to a continuous filrn and be readily dissolved in the laminatingresin, such as a polyester. It is also considered necessary that thefilm forming agent be a stable water emulsion of the cationic characterand be stable through a pH range of 2 to 8. Although certainthermosetting resins are suitable, the thermoplastic resin polymeremulsions are more desirable, and particularly, such materials as thosesynthetic resinous film-forming agents formed from ethylenicallyunsaturated monomers, such as, polybutyl methacrylate, polystyrene,styrene-butadiene copolymer, polyvinyl pyridine, polyvinyl butyral, andpolyvinyl acetate. Experience has indicated the latter resin imparts themore desired binding qualities to the filaments and particularly usefulformulations are known to the trade as Du Ponts Elvacet 81-900 andSwifts 1482-FG Adhesive.

The lubricating ingredient of the present sizing composition performs anumber of functions, for example, it lubricates each filament so as topermit movement thereof relative to other filaments in a strand and alsorelative movement between adjacent strands during plying, twisting, andweaving; the lubricant also regulates the softness and pliability orfeel or hand of the strands; and the lubricant also may act as anemulsion stabilizer, wetting agent, surface-active agent or antistaticagent for modifying the surface characteristics of the glass fibers.

Experience has indicated that each of the foregoing characteristics maysingly or together be imparted to the fibers by incorporating in thesize a lubricant of the type used in the textile industry for the abovepurposes and comprising one or more nonionic or cation types. Typical ofthe lubricants which have been successfuly incorporated in theabove-described sizing compositions are amides of monobasic and dibasicfatty acids, solublized with low molecular weight acids, and ester typeplasticizers. it has also been found that the selection of a particularlubricant depends on the use to be made of the sized glass fibers. Forexample, if the fiber is to be used as continuous length roving, withoutsubstantial twisting or without weaving, strand integrity is not ofparamount importance, but since modification of the surfacecharacteristics is relatively more so, one of the cationic amide typelubricants would be chosen. 1f the fibers are to be plied, twisted, orwoven strand integrity is of highest importance so that a lubricant orcombination of lubricants is chosen which produces the desired softness,pliability, and other characteristics necessary to withstand theseoperations. In the latter case a mixture of the fatty acid amide typeand plasticizer type has. been found most suitable. By the use of one ormore of these lubricant materials in various proportions a sizingcomposition can be derived for any particular usage.

To illustrate, for continuous length roving fiber from 0.01 to 0.50% (onthe total weight of sizing composition) of either a fatty acid amidetype, such as the tetraethylene pentamine amide of pelargonic acid,solubilized with acetic acid or an ester type plasticizer such asdibutyl phthalate will produce roving varying from very such as acrylic,methacrylic and acetic acids.

hard to very soft. For weaving, on the other hand, a

mixture of from 0.01 to 0.50% of the same amide type lubricant and from0.05 to 0.75% of an ester type plasticizer such as dibutyl phthalateproduces a glass strand of a softness adapted to a wide variety ofWeaving operations.

The lubricants of the fatty acid amide types are preferably of thecationic type and may be an amide of a (ii-basic or monobasic acid and apolyethylene polyamine that have been solubilized with loW molecularWeight acids One such amide-type lubricant, which has good surfacemodifying or wetting properties and which has been proven quitesuccessful, is a product designated as RL-l85a which is identified as anamide of pelargonic acid and tetraethylene pentamine solublized withacetic acid. Other suitable lubricants are amides of stearic acid orcaproic acid reacted with polyethylene polyamines such as tetraethylenepentamine, and solublized With low molecular weight acids such as aceticacid.

Ester and polyester type plasticizers have the further characteristicsof providing lubrication in the uncatalyzed state, and are desirably notonly compatible with the film-forming agent, but also are stable aloneand in admixture with said film-forming agent. In addition, theselubricants also should have no adverse eifect on the stability of thevinyl silanol and its ability to form a strong chemical bond with thelaminating resin. Further the lubricant preferably should be non-tacky,nonionic or cationic in nature in order to eliminate fuzzing of theglass fibers during processing, and be moderately soluble or easilydispersible in water emulsions of polyvinyl acetate or equivalentstherefor. Suitable materials of these types include diallyl phthalate,ethylene glycol dimethacrylate, liquid polymerizable polyhydricalcohol-polycarboxylic acid polyesters, diarnyl phthalate, dibutylphthalate, dicarbitol phthalate, dibutoxyglycol phthalate,dimethoxyglycol phthalate, butyl phthalyl butyl glycolate, methylphthalyl ethyl glycolate, triglycol di-Z-ethylbutyrate, triglycoldi-Z-ethylhexoate, tricresyl phosphate, triphenyl phosphate, a materialdesignated as Pluronic F68 which is understood to be a product preparedby condensing ethylene oxide with a hydrophobic base formed by thecondensation of propylene oxide with propylene glycol, a chemicaldesignated as Kapsol which is understood to be methoxyethyloleate, andcompounds known as Plastolein 9715 and Plastolein 9720 which areunderstood to be primarily composed of esters and polyesters of azelaicand pelargonic acids. Of the above materials it has been found thatdibutyl phthalate, tricresyl phosphate and Fluronic F-68 areparticularly suitable.

By way of illustration and not limitation, it may be stated thatapplicants sizing or coating composition may be prepared in thefollowing manner. The various components of the size are measured orweighed in amounts sufficient to produce in the final composition of thesize from 0.50 to 7% and preferably 0.5 to by Weight of a film-formingagent such as polyvinyl acetate, from 0.05 to 5 and preferably 0.10 to1%, of a vinylsilanol as prepared by the ion-exchange method of theabove-mentioned Santelli application, from 0.01 to 1.20%, morepreferably 0.025 to 1%, by weight of lubricant, and water sufficient tobring the total to 100%. Relative to the total content of film-formingagent, the total lubricant content can constitute up to 50% by Weight,although with dibutyl phthalate, RL185a, and other very efi'icientlubricants or softeners it is preferred to utilize less than 30%thereof. However, when utilizing as the lubricant a material such as theabove-noted Kapsol or other similar suitable compounds, it is preferredthat the percentage by weight of lubricant be increased to 1.6%, or 50%by weight of the solids content of polyvinyl acetate emulsion. It iseven more preferred that the total lubricant content be less than 1% byweight of the total sizing composition. The total solids content of thesizing composition can vary from as little as 1.0% to as much as 10%providing the sizing composition is maintained at a viscosity conduciveto the intended mode of application to the fibers.

Subsequent to the measuring of the above materials, one-third of therequired amount of water-is placed in a mixing tank and an agitatorplaced therein, started and allowed to run continuously. The requiredamount of dibutyl phthalate or other lubricant is then added to themeasured portion of poly-vinylacetate with stirring and the mixtureresulting therefrom added to the water in the mixing tank and agitationcontinued. In a separate container the RL-185a, if also employed, isdiluted with five times its weight of water, agitated and then pouredinto the mixing tank containing the binder, other lubricant and water.

Thereafter the measured amount of silicone, as prepared in the mannerdisclosed in the above Santelli application, is also added to the mixing tank followed by the remainder (roughly of the Water. The agitation iscontinued for approximately ten minutes, whereupon the sizing solutionis ready for use in either a pad or roller applicator of other suitabledevice. Should it be desired to employ tricresyl phosphate or Pluronic 1-68 as the lubricant, substantially the same percentage may be used,while-with certain of the other lubricants suggested, suitablepercentage adjustments may be made to produce optimum results.

Glass fibers coated with the above compositions or with otherscontaining either dibutyl phthalate, tricresyl phosphate or PluronicF-68 are then subjected to a heat curing, the length of said curingdepending generally on the ultimate use of the fibrous material. Shouldit be desired to use the fibers in electrical applications, wherein itis considered the silicone component will aid in the stability of thevarnish or lacquer or other coating, the sized fibrous thread or yarn ispreferably heated at 210 F. for three to four hours, depending upon thefiber diameter, to set the film and drive ofi a large part of thelubricant. However, when it is contemplated that the glass fibers Willbe employed in roving form for plastic reinforcements, it is desirablethat the heat curing be lengthened to roughly between six and eighthours at approximately the same temperature so as to evaporate a majorportion of the lubricant and leave on the roving approximately 004% byweight of the lubricant, such as for example, dibutyl phthalate ortricresyl phosphate or Pluronic F-68. The reason for this is thatroving, which comprises a plurality of slight twisted strands made up ofgenerally parallel filaments, is normally chopped into relatively shortlengths of about two inches and said lengths thereafter deposited on amatrix in the formation of the ultimate plastic article. It has beenfound that the strands will open up to the desired degree duringchopping and that the free fall and distribution of the fibers isfacilitated by a lesser amount of lubricant thereon at the time ofchopping, although a relatively greater amount is considered necessaryto avoid filament breakage and drag during the twisting operationspreparatory to making the roving. Also, roving is finding use in acontinuous filament form as a reinforcement material in articles such asfishing rods. In order to provide the desired handleabilitycharacteristics when so employed, it has been found desirable to driveofi the greater part of the lubricant to leave approximately 0.04% byweight thereof on the roving. Glass fibers coated with the present sizewhich are to be twisted, plied or wound, and subsequently used forWeaving into glass cloth, and'thereafter employed to reinforce plastics,are desirably heat cured in the same manner as for electricalapplications.

Example 1 A sizing formulation has been made as described above usingmaterials and proportions as follows:

bilized with acetic aci Elvacet--an aqueous emulsion containing about50% solids.

The above mix Was applied at the bushing by pad applicator to fiberswhich were thereafter wound up on cones into a 225 yarn and dried for 3hours in an oven maintained at 210 F. Material efiiciency in the formingroom was 85% or better. The fibers were then twisted, plied the mixturewas stirred for 10 minutes. The composition of the resulting sizingcomposition Was 4.55% polyvinyl acetate, 0.083% RL-185a, and 0.05 vinylsilanol.

The sizing compositions, as above described, were applied at the bushingusing either a pad or roller applicator. All of the glass rovings wereexcellently bound together without sticking in the roving cones. Afterwinding on cones the rovings were dried in a forced-air oven attemperatures varying from 150 to 225 .F. for periods ranging from 8 to120 hours. Periodically the roving was quantitatively tested for strandintegrity by a hand jerk test and also for choppability. Continuouslengths of rovings were molded into rod-like fishing rod blanks using apolyester resin known as Plaskon 911-11 and tested for dry and wet(after 4 hours boil in water) flexural strengths in order to determinethe percent wet strength retention. The results are summarized as folandconed with 100% efiiciency, very few break-outs belows:

Composition of Sizing Ave.

ution Percen- Ex. Drying Time, Wet No. pH Hrs. Roving Char. Jerk Chop.Strength Poly- Retent vinyl RL-185a Silanol tion Acetate 0 1.0 1-5 8@225F- 90 4. 55 1.0 5-6 8 150 F 76 4. 55 5.0 6-7 16 150 71 4. 55 0. 5 7 12018 75 4. 55 1.0 6.8-7.0 48 180 95 4. 55 1. 5 6. S 710 48 180 84 4. 550.5 5. 2-5. 6 48 180 84 4. 55 0. '50 12 215 85 ing experienced duringtwisting and a minimum of fuzzing during plying and coming. The yarn wasthen woven on standard glass cloth looms to produce a cloth, ineverywise equivalent in appearance to and nearly twice as strong assiliconefinished cloth woven from ordinary starch-oil sized fiber andthen heat-cleaned before applying the silicone finish. A 12-ply laminatewith a styrenated polyester laminating resin was found to have a wetstrength retention of 84%, while a rod-like laminate made from the sizedyarn after storage of the latter for 4 weeks was clear and had a wetstrength retention of 90.4% (amount of dry strength retained afterimmersion in boiling water for four hours). Both the yarn and the clothwere easily wetted by polyester laminating resins of many types.

Examples 2 to 13 Sizing compositions were formulated using materials asfollows:

Material: Percent/wt. Vinyl silanol 0.25 to 5 RL-185a 0 to 0.25Polyvinyl acetate 0 to 7 6 1 Swifts 14 82/FG Adhesivean aqueouspolyvinyl acetate emulsion containing about 50% total Solids 01 whichabout 3% was dibutyl phthalate.

The compositions were prepared by a procedure, identical except foradjustment in the amounts of ingredients, in which 36 liters or 1628grams of a 50% polyvinyl acetate emulsion were added to 0.9 liters ofwater. To this diluted binder emulsion there was then added grams ofRL-185a diluted with 150 grams of Water. Three hundred and ninety gramsof a sodium vinyl siliconate solution (45% concentration) was added to 6liters of Water. This latter solution was. then passed downward througha column five feet tall and six inches in diameter packed withapproximately 25 lbs. of a cation exchange resin known as IR 120. Thedeionized solution was collected and added to the binder mix after whichBy comparison, a roving treated in a similar manner with a well-knownmethacrylato-chromic chloride complex size shows a Wet strengthretention after a 4 hours boil of between only 30 to 40%. Rovingsnumbers 8, 10 and 12, above show no loss of wet-strength retention onstorage for periods ranging from 6 weeks to several months or more. Someof the above treated fibers, for example'No. 6, are sutficiently softand pliable ,to be woven into fabric,

Although the stable aqueous vi-nylsilanol dispersion or solutionproduced in accordance with the method disclosed in the above Santelliapplication Serial No. 279,470 is presently preferred in production'as acomponent of the herein described size, it may at times be founddesirable to substitute therefor a silanol solution prepared by treatinga neutralized siliconate solution either successively or simultaneouslywith anionic or cationic exchange resins. Neutralized siliconatesolutions suitable for use in the latter procedure are disclosed in thecopending applications of Thomas R. Santelli, Serial No. 279,695, filedMarch 31, 1952, and Serial No. 279,690, filed April 1, 1952, nowabandoned, and also assigned to the assignee 0 of the presentapplication.

There is thus disclosed herein a sizing composition by means of whichthe fibrous strands possess the proper degree of high abrasionresistance, integrity, pliability and lubricity. And by a proper balanceof the disclosed ingredients, which permits the accomplishment of thestated characteristics, the fibers may be processed through thetwisting, plying, winding, weaving, drying or cutting operations with noundesirable eitects resulting thereto.

Yet at the same time, by the present composition, good adhesion ispromoted between the'glass fibers and the laminating plastic, which isat least equal to, if not better than, the adhesion resulting from theuse of the organosilicone only as a finish on fabricated forms of glassfibers, such as woven fabrics.

It is thus apparent that there has been eliminated the time-consuming,expensive, and upon occasion, the unsatisfactory procedures of firstlubricating and binding the fibers during formation, removing thismaterial, and applying "a surface treatment in a manner sometimesaccompanied by an additional washing or cleaning operation. There hasalso been eliminated the necessity of certain after-treatments whichwere applied over the conventional lubricants and/or binder to impartdesired properties to the fibers for certain subsequent uses, as inelectrical insulative applications. For such a purpose it may be founddesirable to employ, in place of the unsaturated vinyl silanol of any ofthe aforementioned Santelli applications, a silanol derived by any ofthe described procedures from trifunctional saturated hydrocarbonsilanes, such as, methyl, ethyl,.butyl, phenyl, or mixtures thereof. Asilanol of this type is tightly adherent to the glass and serves toeffectively modify the surface characteristics thereof. Glass somodified has sufiicient affinity for the saturated resins, such aspolyvinyl chloride and the like.

' Such additional operations are herein rendered gener ally unnecessarysince the present size comprises ingredients which impart to the fibersthose characteristics required in substantially every application. Thecoated fibers may be run through all the normal processing operationssuch as twisting, weaving, etc., and may then be used to reinforceplastics, paper and other materials, may be used in electricalapplications, and for such other end uses as are well-known in the art.In short, there is here in disclosed a universal size.

It is to be understood that various modifications may be made in thecompositions and procedures herein disclosed without departing from thespirit and scope of the invention as defined in the appended claims.

We claim:

1. A sizing composition for application to glass fibers during theformation thereof to improve the adhesion thereto of resinous materials,comprising an aqueous emulsion of a synthetic resinous film-formingagent formed from ethylenically unsaturated monomers, a glass fiberlubricating agent, and a deionized hydrolysis product of a vinyl silanolcontaining between 1 and 3 hydrolyzable groups and having anon-hydrolyzable group to silicon atom ratio between 0.8 and 1.5prepared by the cationic deionization of a vinyl siliconate selectedfrom the class consisting of alkali metal vinyl siliconates and alkalineearth metal vinyl siliconates by contact with a hydrogen form of acation active exchanger.

2. A sizing composition of the character defined in claim 1 in which theglass fiber lubricating agent is selected from the class consisting ofmonobasic fatty acid amides and dibasic fatty acid amides solubilizedwith low molecular weight carboxylic acids and mixtures of saidsolubilized amides.

3. A sizing composition for application to glass fibers during theformation thereof to improve the adhesion thereto of resinous materialscomprising the following,

percentages being by weight, from 0.5 to 7.0% of an aqueous emulsion ofa synthetic resinous film-forming agent formed from ethylenicallyunsaturated monomers, from 0.01 to 1.2% of a glass fiber lubricatingagent and from 0.05 to 5% of a deionized hydrolysis product of a vinylsilane containing between 1 and 3 hydrolyzable groups and having anon-hydrolyzable organo group to silicon atom ratio between 0.8 and 1.5,having a pH of from 3 to 8 prepared by cationic deionization of a vinylsiliconate selected from the class consisting of alkali metal vinylsiliconates and alkaline earth metal vinyl siliconates prepared bycontact with the hydrogen form of a cation active exchanger.

4. A sizing composition of the character defined in claim 3 in which thelubricating agent comprises 0.01

to 0.50% of an amide selected from the class consisting of monobasicfatty acid amides and dibasic fatty acid amides, which amide has beensolubilized with a low molecular weight carboxylic acid and mixturesthereof.

5. A stable aqueous emulsion sizing composition suitable for applicationto glass fibers during the formation thereof to improve the adhesionthereto of resinous materials comprising an aqueous emulsion ofpolyvinyl acetate, a glass fiber lubricating aliphatic carboxylic acidamide of polyethylene polyarnine and a deionized hydrolysis product ofvinyl silane containing between 1 and 3 hydrolyzable groups and having anon-hydrolyzable organo group to silicon atom ratio between 0.8 and 1.5prepared by the catonic deionization of a vinyl siliconate selected fromthe class consisting of alkali metal and alkaline earth metal vinylsiliconates by contact with a hydrogen form of a cation activeexchanger.

6. A stable aqueous emulsion sizing composition suitable for applicationto glass fibers during formation thereof to improve the adhesion theretoof resinous materials comprising from 0.5 to 7.0% of an aqueous emulsionof polyvinyl acetate, from 0.01 to 1.2% of a glass fiber lubricatingamide of a C to C aliphatic carboxylic acid and tetraethylene pentamineand a deionized hydrolysis product of a vinyl silane containing between1 and 3 hydrolyzable groups and having a nonhydrolyzable organo group tosilicon atom ratio between 0.8 and 1.5 prepared by the cationicdeionization of a vinyl siliconate selected from the class consisting ofalkali metal vinyl siliconates and alkaline earth metal vinylsiliconates by contact with the hydrogen form of a cation activeexchanger.

7. Glass fibers coated with the composition of claim 1.

References Cited in the file of this patent UNITED STATES PATENTS2,441,423 Elliott et al. May 11, 1943 2,604,688 Slayter July 29, 19522,688,007 Steinman Aug. 31, 1954 OTHER REFERENCES Rochow: Chemistry ofthe Silicons, 2nd Edition, page 54 (1951), John Wiley & Sons, New YorkCity.

1. A SIZING COMPOUND FOR APPLICATION TO GLASS FIBERS DURING THEFORMATION THEREOF TO IMPROVE THE ADHESION THERETO OF RESINOUS MATERIALS,COMPRISING AN AQUEOUS EMULSION OF A SYNETHIC RESINOUS FILM-FORMING AGENTFORMED FROM ETHYLENICALLY UNSATURATED MONBOMERS, A GLASS FIBERLUBRICATING AGENT, AND A DEIONIZED HYDROLSIS PRODUCT OF A VINYL SILANOLCONTAINING BETWEEN 1 AND 3 HYDROLYZABLE GROUPS AND HAVINNG ANON-HYDROLYZABLE GROUPS TO SILICON ATOMS SRATIO BETWEEN O98 AND 195PREPARED BY THE CATIONIC DEIONIZATION OF A VINYL SILICONATE SELECTEDFROM THE CLASS CONSISTING OF ALKALI METAL VINYL SILICONATES AND ALKALINEEARTH METAL VINYL SILIICONATES BY CONTACT WITH A HYDROGEN FORM OF ACATION ACTIVE EXCHANGER.